Underreamer for wells.



UNITED STATES Patented February 14, 1905.

PATENT OEEICE.

JOHN JAMES BREwsTEE, OE SAN FRANCISCO, CALIFORNIA.

UNDERREAIVIER FOR WELLS.

SPECIFICATION forming part of Letters Patent No. 782,320, dated February14, 1905. Y Application filed September 15V, 1904. Serial No. 224,539.

T0 @ZZ whom, t may concern:

Be it known that I, JOHN JAMES BREWSTER, a British subject, residing atSan Francisco, in the county of San Francisco and State` ofCalifornia,have invented a new and useful Underreamer for Wells, ofwhich the following is a speciiication.

The invention relates to improvements in underreamers for wells. vTheobject of the present invention is to improve the construction ofunderreamers for wells and to provide a simple, inexpensive, andeiiicient tool of this character adapted to be readily passed throughawell-casing to introduce it into the bottom of a well and capable ofreaming or enlarging the bottom and oi' being readily withdrawn throughthe well-casing after the reaming operationy has been completed.

A further object of the' invention is to provide a tool of thischaractercapable of passing through a well-casing in a contracted condition andof being readily expanded and ar'- ranged for operation after passingthrough the said casing and of beingconveniently returned tozitscontracted or inoperative condi tion to enable it to be withdrawn.

Another object of the invention is to provide a bottOm-reamer having aplurality of movable bits or cutters which will produce a round hole andwhich will loe so constructed thatpebbles and small stones will notinterfere with their operation when withdrawing the tool.

With these and other objects in View the invention consists in theconstruction and novel combination and arrangement of parts hereinafterfully described, illustrated in the accompanying drawings, and pointedoutl in the claims hereto appended, it being understood that various'changes in the form, proportion, size, and minor details ofconstruction within the scope .of the claims may be resorted towithoutdeparting from the spirit or sacriiicinganyof theadvantages ofthe invention.

In the drawings, Figure 1 is an elevation of an underreamer-'constructedin accordance with this 'in tion| and shown arranged for operation,y i62 is a longitudinal sectional triangular, as shown.

View of the same, the bits or cutters being extended longitudinally forcontracting the diameter of the tool. Fig. 3 isa longitudinal sectionalview of a portion of the tool, the parts being arranged as shown in Fig.l. Fig.

4 is a transverse sectional view on the line4 4 ofFig. 2. Fig. 5 isasimilar view on the line 5 5 of Fig. Q. Fig. 6 is `a longitudinalsectional view taken at right angles to Fig. 2 and'illustrating thearrangement of the upper and lower blocks and the rods for retaining thesame in the ways of the body. Fig. 7 is a detail view illustrating theconstruction of the ways otl the body. Fig. 8 is a detail perspectiveview of one of the bits or cutters.

Lilie numerals of reference designate corresponding parts in all thefigures of the drawings.

`1 designates thebody of the tool, which isv circular in cross-sectionand which is provided at its upper end with a reduced portion or shank2, adapted to be secured to the shaft or other operating mechanism, andany means may be employed for effecting such connection. The body of thetool is provided with a plurality of longitudinal ways 3, consisti'ng ofgrooves vor channels and receiving bits or cutters 4,

having inwardly-tapered lower portions 5,y presenting angularly-disposedinclined faces 6 and forming wedges adapted, as hereinafter explained,to force the cutting portions of the bits or cutters Outward, wherebythe bits or cutters are expanded to the position illustrated in Figs. land 3 of the drawings. The upwardly-tapered lower portion 5 is alsoprovided with inclined side faces, as clearly illustrated in Figs. l and8 of the drawings, and the lower end 7 of the bit or cutter isoppositely beveled to provide'a transverse cutting edge which inclinesupwardly and inwardly, the lower end faces of the bits or cutters beingbeveled or cut away, as shown in Fig. 3, to produceouter'cuttingA-points. "The cutting portions, which taper to a point atthe outer faces of the bits or cutters, are approximately The taperedlower portion of the bit or cutter is also recessed or cut body of thebit is provided with a flat face, and the cutting portions of the bitsor cutters extend downward slightly beyondthe plane of the lower face ofthe body, as shown in Fig. 3, and the reamer is adapted to produce around hole, and there is no liability of small stones,`pebbles, or otheraccumulation interfering with the operation of the bitsv or cutters whenwithdrawing the tool, as hereinafter explained. The particularconstruction of the lower ends of the bits or cutters provides spaces orpassages for permitting water to How freely around the tool. The lowerportions 9 of the ways or channels 3 of the body are tapered to receivethe tapered lower portions of the bits or cutters, as clearly shown inFig. 1 of the drawings.

The bits or cutters 4 are provided with integral Shanks or barsrectangular in crosssection, as clearly shown in Fig. 8 of the drawings,and provided with opposite laterally-extending flanges l0, which slidein longitudinal grooves 11, formed in the opposite walls of the ways orchannels and permitting the bits or cutters to move longitudinally alimited distance to enable the said cutters to assume either theposition illustrated in Fig. 1 or that shown in Fig. 2. The upperportions ofthe longitudinal grooves 1l are formed by grooving the wallsof the channels or ways, and the lower portions of the grooves areformed by upper and lower blocks 12 and 13, arranged in pairs and set inrecesses, the vinner faces of the blocks being Hush with the outer wallsof the upper portions of the grooves.Y The lower blocks, which are of alength slightly in excess of the length of the lianges l0, when' removedprovide entrances to the longitudinal grooves 11 and enable the bits orcutters to be readily introduced into the channels or ways and removedtherefrom. When it is desired to remove a bit or cutter, the lowerblocks are detached, as hereinafter explained, and the bit or cutter isdrawn downward until the flanges are brought opposite the entrancesformed by removing the lower blocks. The bit or cutter may then bereadily removed from the body of the tool. The upper blocks areinterlocked with the walls of 4the channels or ways by means oflongitudinal tongues 14, formed integral with the blocks 12 and fittingin corresponding grooves of the wallsof the recesses 15. The upper andlower blocks are provided with registering longitu-V dinal bores 16 and17 for the reception of longitudinal rods 18, which are arranged inbores 19 and 20, located above and below the blocks, as clearly shown inFig. 6 of the drawings. The body of the tool is provided above the upperportions 19 of the bores with grooves or channels 21 for the receptionof the attachment-rods, which have heads 22 at their upper ends. Theheads 22 are engaged by an internally-threaded collar 23, arranged on athreaded portion 24 of the-shank 2 of the tool.

Any suitable means may be provided for removing the threaded collar, andwhen the same is detached the rods may be readily withdrawn suiiicientlyto permit the' removal of the lower rods.v

The bits or cutters are provided at their inner faces with intermediaterounded portions or enlargements 25, fitting against the inner or rearwalls of the ways or channels when the parts are arranged as ,shown inFigs. l and 3 of the drawings and fulcruming the bits or cutters forenabling the lugs 26 to be readily disengaged from upper shoulders 27when it is desired to arrange the bits or cuttersfor removing the tool.When the bits or cutters are arranged for operation., there is a spacebetween the lower ends of the cutters and the inner walls of thechannels orways 3, as shown at 28 in Fig. 3 of the drawings, whereby thelower arm or portion lying below the enlargement 25 is adapted to beswung inward to disengage the said lug 26 from the shoulder 27. Thisdisengagement is effected by drawing the tool upward until the lower endof the casing strikes the outer faces of the lower portions of the bitsor cutters, which will be swung inward by such Contact. The lug 26,which extends inward from the upper end of the bit or cutter, as clearlyshown in Figs. 1, 3, and 8, forms a hook-shaped portion and is slightlyinclined when the tool is in condition for operation. The inner or rearwalls of the channels or ways are recessed at the upper portions toprovide a shoulder 27 and a shoulder 29, which is arranged slightlybelow .the shoulder 27 and which receives the lug 26 when the bits orcutters are extended longitudinally to contract the toolcircumferentially. The shoulder 29 receives the lug 26 when the bits orcutters are `extended longitudinally and supports the tool, as clearlyshown in Fig. 2. When the 'bit or cutter is supported by the shoulder29, the laterally-extending anges do not extend to the lower ends of thelower blocks. The body of the tool is provided at its lower portion withcurved recesses 30, formed in the inner or rear walls of thelongitudinal ways or channels to receive the rounded enlargements 25when the tool is contracted. rlhe inner or rear walls of the ways orchannels 3 and the upper portions of the opposite grooves l1 areinclined and enlarged to permit the necessary movement of theanges 10when the bits or cutters are moved upward in the ways or channels -forengaging the lug 26 with the shoulder 27 and also IOO IIO

when the upper portions of the bits or cutters l are moved outward todisengage the lugs 26 from the shoulders 27. 'i

The tool is introduced into a well-casing with the bits or cuttersarranged as shown in Fig. 2, and when the said bits or cutters con. tactwith the bottom of the well the weight of the tool will cause the bodyportion to continue its downward movement until the upper ends of thebits or vcutters engage the upper end walls of the ways or channels.This movement of the body relative to the bits or cutters will cause thelower cutting portions of the latter to move outwardly by reason of theinclined inner faces 6 engaging the lower end of the body. When the bodyhas reached the limit of its downward movement, a slight lifting of thecable, to which the tool is attached, will cause the lugs to dropinwardly on the seats formed by the shoulders 26. The shoulders 26incline downwardly and inwardly, and the upper end walls of the Ways orchannels are also similarly inclined. The downward pressure on the toolwill hold the bits or cutters firmly in position for boring, and as soonas the bits or cutters are relieved of such pressure they will be incondition for operation by the well-casing.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is-

1. A tool of the class described, comprising a body, and a bit or cuttermovably mounted on the body in a longitudinal direction and arranged toextend beyond the lower end of the body, whereby the weight of thelatter will move the same upward on it when the tool cornes in contactwith the bottom of a well, said bit or cutter having an oppositely-vbeveled lower end and tapered upwardly above the same at both the sidesand back to present inclined innerv and side faces 2. A tool of theclass described, comprising a body, a bit or cutter movably mounted onthe body in a longitudinal direction and arranged to extend beyond thelower end of the body, whereby the weight of the latter will move thesame inward on it when the tool comes in contact with thev bottom of awell, means for automatically moving A the bit or cutter outwardsimultaneously with the inward movement of the same on the body, and afulcrum located between the ends of the bit or cutter, the saidbit'orcutterhaving 4its portion below the fulcrum spaced from the bodyand adapted to move inwardly.

3. A tool of the class described, comprising a body having a way orchannel and provided at the upper portion thereof with a seat, and alongitudinally-movable bit or cutter provided at its upper portion witha lug for engaging the seat and having a lower tapered portion, said bitor cutter being provided with an intermediate fulcrum.

e. A tool of the class described, comprising a body having a way orchannel and provided at the upper portion thereof with a seat and havinga recess at an intermediate point, and a longitudinally-movable bit orcutter provided at its upper portion with a lug for engaging'tbe seatand having a lower tapered portion, said bit or cutter beingprovided'with an intermediate fulcrum, said intermediate fulcrum beingadapted to fit in the recess of the body when the tool is contracted.

5. A tool of the class described, comprising a body having a way andprovided with recesses, a bit or cutter slidablein the way and providedwith laterally extending flanges, blocks mounted on the body in therecesses thereof and forming entrances to the said way when removed, andmeans for detachably securing the blocks in position.

6. A tool of the class described, comprising `a body having a way andprovided with recesses, a bit or cutter slidable in the way and providedwith projecting anges, upper and lower blocks arranged in the recesses,the upper blocks being interlocked with the body, and the lower blocksbeing removable to provide entrances to the way, and rods passingthrough the blocks and engaging the body above and below thesame. Y

7. A tool of the class described, comprising a body having a way andprovided with recesses, a bit or cutter slidable in the way and providedwith projecting ianges, upper and lower blocks arranged inthe recesses,the upper blocks being interlocked with the body, and the lower blocksbeing removable to provide entrances to the way, rods passing throughthe blocks and engaging the body above and below the same, and aremovable collar mounted on the body andl engaging the rods.

8. A tool of the class described, comprising a body having alongitudinal way and provided at opposite sides thereof with grooves andhaving recesses, a slidable bit or cutter having flanges -arranged inthe'V grooves, re-

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movable blocks mounted on the body inthe recesses thereof, rods engagingthe bores ofy the body and the blocks at opposite ends of the latter,said body being also grooved beyond the bores to receive the rods, andthe latter being provided with heads, and means for engaging the headsofthe rods for retaining the latter in position.

ln testimony that l claim the foregoing as my own I have hereto aiiixedmy signature in' the presence of two witnesses.

JOHN JAMES BREWSTER. Witnessesz' A. K. DAGGETT, W. E. voN JoHANNsEN.

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